Effect of initiator concentration, exposure time and particle size of the filler upon the mechanical properties of a light-curing radiopaque dental composite

Context:The quality of light curing units can profoundly influence mechanical properties of dental composite materials. Aim: To compare effect of Woodpecker RTA Mini-S and Elipar Deep Cure-L curing units onmechanical properties (compressive strength, diametral tensile strength and microhardness) of Filtek Bulk-Fill. Methods and Materials: A total of 32 samples of Filtek Bulk Fill composite were divided into 2 equal groups (n=16). 12 samples in each group were fabricated using a tooth shaped mold and 4 in circular rings to test compressive strength, microhardness and diametral tensile strength, respectively. Theblocks were evaluated for the above parameters using Universal Testing Machine and Vickers Microhardness Tester.Independent sample-t test was used in this study (p< 0.05). Results: The results of this study showed that the group of composites cured using Elipar Deep Cure-L curing unit showed better mechanical properties and the difference between the groups was statistically significant for compressive strength and diametral tensile strength (p < 0.05) Conclusion: It was concluded that a curing unit of higher intensity and quality of output used in conjugation with bulk fill composites are likely to give better results.

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The influence of filler amount on selected properties of new experimental resin dental composite

Open Chemistry ◽

10.1515/chem-2018-0090 ◽

2018 ◽

Vol 16 (1) ◽

pp. 905-911 ◽

Cited By ~ 1

Author(s):

Kinga Bociong ◽

Agata Szczesio ◽

Michal Krasowski ◽

Jerzy Sokolowski

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Flexural Strength ◽

Dental Composite ◽

Neat Resin ◽

Light Curing ◽

Contraction Stress ◽

Silanized Silica ◽

Composite Hardness ◽

Diametral Tensile Strength

AbstractAim of the study was to evaluate the influence of filler amounts on mechanical properties and contraction stress of light-curing experimental composite. Hardness, flexural strength, diametral tensile strength of material filled with 40, 50 or 60 wt. % of silanized silica were tested. The contraction stress was measured after 24 h by means of photoelastic study. The addition of 40-60 wt. % filler to composite caused significant increase in hardness, Young’s modulus and flexural strength. The DTS, after incorporating filler into polymer matrix, was valued at ~26 MPa. The composite containing 40 wt. % of filler demonstrated significantly lower contraction stress in comparison to neat resin and filled > 50 wt. % of silica.

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Study of POSS on the Properties of Novel Inorganic Dental Composite Resin

Polymers ◽

10.3390/polym12020478 ◽

2020 ◽

Vol 12 (2) ◽

pp. 478 ◽

Cited By ~ 6

Author(s):

Jiahui Wang ◽

Yizhi Liu ◽

Jianxin Yu ◽

Yi Sun ◽

Weili Xie

Keyword(s):

Mechanical Properties ◽

Composite Resin ◽

Dental Composite ◽

Resin Composites ◽

Dental Resin ◽

Dental Resin Composites ◽

Dental Composite Resin ◽

Light Curing ◽

Curing Method ◽

Oligomeric Silsesquioxane

Various amounts of methacryl polyhedral oligomeric silsesquioxane (POSS) were explored to be incorporated into novel nano SiO2 dental resin composites using light curing method. The scanning electron microscopy (SEM), optical microscopy, fourier transform infrared spectroscopy (FTIR), nanoindentation, nanoscratch and three-point flexure tests were performed. The volumetric shrinkage and mechanical properties such as hardness, elastic modulus, resistance, flexural strength and fracture energy were analyzed. With the additions of POSS, the volume shrinkage decreased and the mechanical properties initially increased. The effects of POSS on these properties were studied to provide a reference for clinically selecting a composite resin with excellent properties.

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Curing parameters to improve the mechanical properties of stereolithographic printed specimens

Rapid Prototyping Journal ◽

10.1108/rpj-11-2016-0180 ◽

2018 ◽

Vol 24 (1) ◽

pp. 46-51 ◽

Cited By ~ 10

Author(s):

Matthew P. Watters ◽

Michelle L. Bernhardt

Keyword(s):

Mechanical Properties ◽

Compressive Strength ◽

Layer Thickness ◽

Surface Quality ◽

Exposure Time ◽

Content Type ◽

Curing Methods ◽

Effective Depth ◽

Light Curing ◽

Printing Parameters

Purpose This paper presents findings from a study examining curing procedures to improve the compressive strength and hardness properties of specimens while maintaining surface quality. All specimens were created from a standard grey, acrylic-based photopolymer and fabricated using stereolithography technology. This paper aims to investigate the effects of printing layer thickness and print orientation on specimen compressive strength, as well as the effects of thermal and light curing methods. In addition, the post-print curing depth was investigated. Design/methodology/approach The effects of layer thickness and print orientation were investigated on 10 × 20 mm cylinders by determining the ultimate compressive strength once cured. The compressive strength of cylinders subjected to varying thermal and light settings was also investigated to determine the optimal curing settings. The effective depth of curing was investigated on a 25.4-mm cuboidal specimen, which received both thermal and light curing. Findings To achieve the highest compressive strength, specimens shall be printed with the minimal layer thickness of 25 µm. Increasing temperatures up to 60° C during curing provided a 0.75-MPa increase in compressive strength per degree Celsius. However, increasing temperatures above 60° C only provided a 0.15-MPa increase in compressive strength per degree Celsius. Furthermore, curing temperatures above 110° C resulted in degraded surface quality noted by defects at the layer laminations. Specimens required a minimum light curing exposure time of four hours to reach the maximum cure at which point any increase in exposure time provided no substantial increase in compressive strength. Originality/value This study provides recommendations for printing parameters and curing methods to achieve the optimum mechanical properties of cured stereolithography specimens.

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Effect of SiC particle size and severe deformation on mechanical properties and thermal conductivity of Cu/Al/Ni/SiC composite fabricated by ARB process

Journal of Manufacturing Processes ◽

10.1016/j.jmapro.2021.07.017 ◽

2021 ◽

Vol 68 ◽

pp. 57-68

Author(s):

Jianping Huang ◽

Moslem Tayyebi ◽

Amir Hossein Assari

Keyword(s):

Mechanical Properties ◽

Thermal Conductivity ◽

Particle Size ◽

Severe Deformation ◽

Sic Particle

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Experimental Analysis of the Mechanical Properties and Resistivity of Tectonic Coal Samples with Different Particle Sizes

Energies ◽

10.3390/en14082303 ◽

2021 ◽

Vol 14 (8) ◽

pp. 2303

Author(s):

Congyu Zhong ◽

Liwen Cao ◽

Jishi Geng ◽

Zhihao Jiang ◽

Shuai Zhang

Keyword(s):

Mechanical Properties ◽

Particle Size ◽

Compressive Strength ◽

Elastic Modulus ◽

Uniaxial Compressive Strength ◽

Coalbed Methane ◽

Coal Sample ◽

Fine Particles ◽

Particle Sizes ◽

Tectonic Coal

Because of its weak cementation and abundant pores and cracks, it is difficult to obtain suitable samples of tectonic coal to test its mechanical properties. Therefore, the research and development of coalbed methane drilling and mining technology are restricted. In this study, tectonic coal samples are remodeled with different particle sizes to test the mechanical parameters and loading resistivity. The research results show that the particle size and gradation of tectonic coal significantly impact its uniaxial compressive strength and elastic modulus and affect changes in resistivity. As the converted particle size increases, the uniaxial compressive strength and elastic modulus decrease first and then tend to remain unchanged. The strength of the single-particle gradation coal sample decreases from 0.867 to 0.433 MPa and the elastic modulus decreases from 59.28 to 41.63 MPa with increasing particle size. The change in resistivity of the coal sample increases with increasing particle size, and the degree of resistivity variation decreases during the coal sample failure stage. In composite-particle gradation, the proportion of fine particles in the tectonic coal sample increases from 33% to 80%. Its strength and elastic modulus increase from 0.996 to 1.31 MPa and 83.96 to 125.4 MPa, respectively, and the resistivity change degree decreases. The proportion of medium particles or coarse particles increases, and the sample strength, elastic modulus, and resistivity changes all decrease.

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Effect of Particle Size on Mechanical Properties and Fracture Behaviors of Age-Hardening SiC/Al–Zn–Mg–Cu Composites

Acta Metallurgica Sinica (English Letters) ◽

10.1007/s40195-021-01254-w ◽

2021 ◽

Author(s):

Guonan Ma ◽

Dong Wang ◽

Bolv Xiao ◽

Zongyi Ma

Keyword(s):

Mechanical Properties ◽

Particle Size ◽

Age Hardening ◽

Fracture Behaviors ◽

Effect Of Particle Size

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The Influence of Different Plasma Cell Discharges on the Performance Quality of Surgical Gown Samples

Materials ◽

10.3390/ma14154329 ◽

2021 ◽

Vol 14 (15) ◽

pp. 4329

Author(s):

Atif H. Asghar ◽

Ahmed Rida Galaly

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Exposure Time ◽

Electrical Characteristics ◽

Cathode Fall ◽

Treatment Efficiency ◽

Performance Quality ◽

Surgical Gown ◽

The One

An experimental study was performed on a low-density plasma discharge using two different configurations of the plasma cell cathode, namely, the one mesh system electrodes (OMSE) and the one mesh and three system electrodes (OMTSE), to determine the electrical characteristics of the plasma such as current–voltage characteristics, breakdown voltage (VB), Paschen curves, current density (J), cathode fall thickness (dc), and electron density of the treated sample. The influence of the electrical characteristics of the plasma fluid in the cathode fall region for different cathode configuration cells (OMSE and OMTSE) on the performance quality of a surgical gown was studied to determine surface modification, treatment efficiency, exposure time, wettability property, and mechanical properties. Over a very short exposure time, the treatment efficiency for the surgical gown surface of plasma over the mesh cathode at a distance equivalent to the cathode fall distance dc values of the OMTSE and for OMSE reached a maximum. The wettability property decreased from 90 to 40% for OMTSE over a 180 s exposure time and decreased from 90 to 10% for OMSE over a 160 s exposure time. The mechanisms of each stage of surgical gown treatment by plasma are described. In this study, the mechanical properties of the untreated and treated surgical gown samples such as the tensile strength and elongation percentage, ultimate tensile strength, yield strength, strain hardening, resilience, toughness, and fracture (breaking) point were studied. Plasma had a more positive effect on the mechanical properties of the OMSE reactor than those of the OMTSE reactor.

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